Hotels haven't yet gone full Minority Report, allowing guests to use biometric eyeball scans, rather than a card or key, to enter their rooms. Nor are robot butlers a thing. But we may not be far off.

Artificial intelligence is already in hotel rooms, with Amazon's Alexa-enabled devices taking commands from guests at some Best Westerns, Dream Hotels, and Marriotts. Now, with the global biometrics industry expected to top $30 billion in three years, according to ABI research, at least one hotel business is trying its hand at analyzing the biometrics of its clientele.